Hearing impairment and cognitive decline: a pilot study conducted within the atherosclerosis risk in communities...

Hearing impairment (HI) is prevalent, is modifiable, and has been associated with cognitive decline. We tested the hypothesis that audiometric HI measured in 2013 is associated with poorer cognitive function in 253 men and women from Washington County, Maryland (mean age = 76.9 years) in a pilot study carried out within the Atherosclerosis Risk in Communities Neurocognitive Study. Three cognitive tests were administered in 1990-1992, 1996-1998, and 2013, and a full neuropsychological battery was administered in 2013. Multivariable-adjusted differences in standardized cognitive scores (cross-sectional analysis) and trajectories of 20-year change (longitudinal analysis) were modeled using linear regression and generalized estimating equations, respectively. Hearing thresholds for pure tone frequencies of 0.5-4 kHz were averaged to obtain a pure tone average in the better-hearing ear. Hearing was categorized as follows: ≤25 dB, no HI; 26-40 dB, mild HI; and >40 dB, moderate/severe HI. Comparing participants with moderate/severe HI to participants with no HI, 20-year rates of decline in memory and global function differed by -0.47 standard deviations (P = 0.02) and -0.29 standard deviations (P = 0.02), respectively. Estimated declines were greatest in participants who did not wear a hearing aid. These findings add to the limited literature on cognitive impairments associated with HI, and they support future research on whether HI treatment may reduce risk of cognitive decline.